Mr. J. E. Gray on Hyperoodon latifrons. 407 



Distinguished chiefly from H. vesicula by the less ventricose 

 form of the last whorl, the shorter reflexion at the top of the 

 pillar lip, and by the aperture, which is broader than long in 

 this species, and has not the vertical position of the columellar 

 lip, so conspicuous in that shell. It varies much also in the rela- 

 tive height of the spire. 



6. Helix suhjecta, nobis, n. s. 



Testa obtecte perforata, orbiculato-conoidea, striata, nitidiuscula, cornea, 

 translucente ; spira acutiuscula, sutura submarginata ; anfractibus 

 6, ultimo latiori, rotundato ; apertura vix obliqua, late lunari ; 

 peristomate simplici, recto, margine columellari oblique descen- 

 dente, supenie late triangulari-reflexo, perforationem obtegente. 



Diam. major 17, minor 14, axis 8^ mill. 



Hab. in montibus BengaHae, non procul ab urbe Rajmahal. Teste 

 Dr. Bacon. 



Distinguished from the two last-described shells by the colour, 

 proportion of the last whorl, and characters of the aperture. It 

 was sent to Dr. Pfeiffer to be figured under the MSS. name of 

 " spreta" which has been now altered with reference to the 

 prior use of that name by Adams. 



London, April 10, 1852. 



XXXV. — Observations on Hyperoodon latifrons. 

 By J. E. Gray, Ph.D., F.R.S., V.P.Z.S. &c. 



In Professor Eschricht^s paper on the Gangetic Dolphin, so well 

 translated by Dr. Wallich, he observes, first referring to a pre- 

 vious paper of his own, " Mr. Gray^s Hyperoodon latifrons is a 

 good species founded on a cranium from the Orkney Islands, 

 with the crest of the upper jaw unusally thick, and yet it may 

 perhaps be only the cranium of an old male of the common 

 Hyperoodon." He then proceeds : " This supposition has since 

 become a matter of certainty, for all the crania of old Hyper- 

 oodons, at least of males, have the crest similarly developed, as 

 has actually been verified in a skeleton of an old individual of 

 this kind sent to my worthy colleague Professor Steenstrup 

 from the Faroe Islands." 



It appears from the above paragraph, that the only reason 

 which Professor Eschricht has for pronouncing " all the crania 

 of old Hyperoodons, at least of males, to have the crests simi- 

 larly developed," is that a single specimen of the animal, which 

 has been found in Faroe Islands, was a male. Now I was 

 assured by the fishermen who procured the head which I do- 



